Question

Li→ Li2O→LiOH
Ba→BaO→Ba(OH)2
S→SO2→SO3→H2SO4
H2O2→H2O→O2→P2O3

Answer 1

2Li + O = Li2O
Li2O + H2O = 2LiOH
Ba + O = BaO
BaO + H2O = Ba(OH)2